OP0073 NEW PERSPECTIVES IN AXIAL SPONDYLOARTHRITIS - FIRST RESULTS OF GENDER-SPECIFIC ASSESSMENT OF MRI IMAGING CRITERIA
Authors: S. T. Ulas, F. Proft, T. Diekhoff, V. Rios Rodriguez, J. Rademacher, M. Protopopov, S. Ohrndorf, D. Poddubnyy, K. Ziegeler
Journal: Annals of the Rheumatic Diseases (2022)

Background Gender-specific differences in patients with axial spondyloarthritis (axSpA) are often seen in the clinical presentation and may differ in MRI findings 1 . Male axSpA patients tend to show structural changes earlier, whereas in female axSpA patients the peripheral joints are more often affected 2 . This can lead to a delay in axSpA diagnosis in women. For this reason, gender-specific data collection and establishment of gender-specific imaging criteria are of particular importance. Objectives To evaluate the diagnostic performance of different combinations of imaging markers to derive data-driven imaging criteria for MRI in axSpA, separately for men and women. Methods A total of 1194 patients were included in the study. Considering the exclusion criteria (available MRI image data sets, confirmed diagnoses), 684 patients (379 axSpA and 305 control group) were included for further statistical analysis. Two trained readers scored the MRI images separately for the presence of ankylosis, as well as erosion, sclerosis, fat metaplasia, and bone marrow edema differentiated for 3 regions (ventral/mid/dorsal) for sacral-sided and iliac-sided sacroiliac joint. Chi^2 test was applied to compare lesion frequencies per group. Contingency table analysis was performed to assess diagnostic performances. The diagnostic performances were compared using the diagnostic odd ratio (DOR). Results Overall, 136 female and 243 male axSpA patients were included. Higher prevalence for ankylosis (24.3 vs. 7.4%) and fat metaplasia (58.8 vs. 42.6%) was shown in male axSpA patients; in contrast, sclerosis was more common in female axSpA patients (75.0 vs. 57.6%). No sex differences in frequency were shown for bone marrow edema and erosion. In male axSpA patients, the most significant difference in individual parameters was shown for ankylosis (DOR 40.1) compared with females (DOR 4.7). The detection of erosion and fat metaplasia as markers was also better in male axSpA patients (DOR 17.6 vs. 11.1 and 18.6 vs. 6.3). Sclerosis and bone marrow edema were better suited in female axSpA patients (DOR 3.0 vs. 2.5 and 5.0 vs. 3.7). Overall, diagnostic accuracy was improved when only lesions in the middle and dorsal articular compartments were considered. Conclusion The diagnostic performance of established image markers on MRI is significantly lower in female axSpA patients. This is especially true for ankylosis, which provides the risk for false-positive findings in women. Based on these findings, future revisions of imaging criteria may include gender-specific recommendations to improve diagnostic accuracy for male and female axSpA patients. References [1]Braun J, Baraliakos X, Bülow R, et al. Striking sex differences in magnetic resonance imaging findings in the sacroiliac joints in the population. Arthritis Res Ther. 2022 Jan 20;24(1):29. doi: 10.1186/s13075-021-02712-7. [2]Mease PJ, McLean RR, Dube B, et al. Comparison of Men and Women With Axial Spondyloarthritis in the US-based Corrona Psoriatic Arthritis/Spondyloarthritis Registry. J Rheumatol 2021;48(10):1528-36. doi: 10.3899/jrheum.201549 [published Online First: 2021/04/17] Disclosure of Interests Sevtap Tugce Ulas: None declared, Fabian Proft Speakers bureau: Novartis, Lilly and UCB, as well as personal fees from AbbVie, AMGEN, BMS, Hexal, Janssen, MSD, Pfizer and Roche, Grant/research support from: Novartis, Eli Lilly and UCB., Torsten Diekhoff Speakers bureau: MSD, Novartis and Eli Lilly., Valeria Rios Rodriguez Speakers bureau: AbbVie and Falk e.V., Judith Rademacher Grant/research support from: Berlin Institute of Health (BIH) during the conduct of this study (Clinician Scientist Programme)., Mikhail Protopopov Grant/research support from: UCB, Sarah Ohrndorf: None declared, Denis Poddubnyy Speakers bureau: AbbVie, Eli Lilly, MSD, Novartis, Pfizer, Bristol-Myers Squibb, Roche, UCB, Biocad, GlaxoSmithKline and Gilead, Grant/research support from: AbbVie, Eli Lilly, MSD, Novartis and Pfizer., Katharina Ziegeler Grant/research support from: Assessment of Spondyloarthritis international Society (ASAS) during the conduct of this study.